Plot cumulative value for different series - r

Question

I have run a short simulation and want to plot the outcomes of each simulation in terms of the "running sum" over parameter k. For reference, I want to end up with a plot that looks similar to the ones in this article:
https://www.pinnacle.com/en/betting-articles/Betting-Strategy/betting-bankroll-management/VDM2GY6UX3B552BG
The following is the code for the simulation:
## Simulating returns over k bets.
odds <- 1.5
k <- 100
return <- odds - 1
edge <- 0.04
pw <- 1/(odds/(1-edge))
pl <- 1-pw
nsims <- 10000
set.seed(42)
sims <- replicate(nsims, {
x <- sample(c(-1,return), k, TRUE, prob=c(pl, pw))
})
rownames(sims) <- c(1:k)
colnames(sims) <- c(1:nsims)
If I wasn't being clear in the description let me know.

Answer 1

Okay so here is how you can achieve the plot of the cumulative value over bets (I set nsims <- 10 so that the plot is readable).
First I generate the data :
## Simulating returns over k bets.
odds <- 1.5
k <- 100
return <- odds - 1
edge <- 0.04
pw <- 1/(odds/(1-edge))
pl <- 1-pw
nsims <- 10
set.seed(42)
sims <- replicate(nsims, {
x <- sample(c(-1,return), k, TRUE, prob=c(pl, pw))
})
rownames(sims) <- c(1:k)
colnames(sims) <- c(1:nsims)
Then I create a dataframe containing the results of the n simulations (10 here) :
df <- as.data.frame(sims)
What we want to plot is the cumulative sum, not the result at a specific bet so we iterate through the columns (i.e. the simulations) to have that value :
for (i in colnames(df)){
df[[i]] <- cumsum(df[[i]])
}
df <- mutate(df, bets = rownames(df))
output <- melt(df, id.vars = "bets", variable.name = 'simulation')
Now we can plot our data :
ggplot(output, aes(bets,value,group=simulation)) + geom_line(aes(colour = simulation))